Method for filling and sealing a root canal

ABSTRACT

A root canal is filled and/or sealed using a hydrophilic sealing composition, optionally in combination with other filling materials. The sealing composition may include one or more resins that promote adhesion to hydrophilic dental tissues. The composition may be introduced into the root canal using a narrow cannula coupled to a high pressure hydraulic delivery device. In the case where a chemical cure composition is used to seal the root canal, a chemical initiator can be used to cause the mixed composition to harden over time. Hardening of at least a portion of the composition can be accelerated by including a photoinitiator and irratiating the mixed composition with radiant energy (e.g., from a dental curing lamp).

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of U.S. application Ser. No.10/441,734, filed May 20, 2003, which is a division of U.S. applicationSer. No. 10/121,389, filed Apr. 12, 2002, now issued U.S. Pat. No.6,652,282, which is a continuation of U.S. application Ser. No.09/736,729, filed Dec. 14, 2000, now issued U.S. Pat. No. 6,500,004. Forpurposes of disclosure, the foregoing applications and patent areincorporated by reference.

BACKGROUND OF THE INVENTION

[0002] 1. The Field of the Invention

[0003] The invention is in the field of compositions and methods forsealing a root canal during an endodontic procedure. More particularly,the invention involves compositions having enhanced adhesion tohydrophilic dental tissues found within root canals which assists theirability to effectively seal and protect a newly cleaned root canal. Suchcompositions are preferably radiopaque and are cured more rapidlycompared to existing endodontic sealing compositions, thus allowing forquicker placement of a final filling or crown to complete the root canalprocedure.

[0004] 2. The Relevant Technology

[0005] Following an endodontic root canal procedure, in which the rootcanal is cleaned using special root canal tools and irrigation devices,it is important to fill and seal the evacuated root canal in order topreserve the dead tooth from further decay that might compromise theintegrity of the tooth and cause infection. In a typical procedure, oneor more soft, resilient, needle-like inserts known as “gutta percha”points are inserted in each root canal branch in order to at leastpartially seal and fill the root canal.

[0006] The term “gutta percha” refers to a rubbery material derived fromnatural rubber, typically blended with zinc oxide. This particularrubbery material is preferred because it is compressible, flexible andrelatively soft so that it can be used to fill voids within the exposedroot canal. The gutta percha points are typically impregnated with othermaterials such as radiopaque solids, zinc oxide, for its medicinalproperties, and other passive or active ingredients as desired. It isimpossible, however, to completely seal a root canal from all ingress offluids, which may be laden with bacteria, using gutta percha alone.Conventional techniques require multiple gutta percha cones per canaland laborious “later condensation” techniques. For some, it requiresheating the gutta percha in an attempt to make it flow into the lateralcanals. However, this technique, coupled with the properties of guttapercha, make it hard to achieve fine adaptation to canal walls and flowinto the dentinal tubules.

[0007] The filling and sealing of the root canal can be further enhancedby inserting flowable materials, such as antiseptic pastes and/orsealing resins along with the gutta percha points. Due to the highviscosity of typical antiseptic pastes, such as zinc oxide/eugenol, orsealing resins, which tend to be epoxy-based, such materials are firstapplied to the gutta percha and then inserted into the root canal alongwith each gutta percha point. Alternatively, they may be inserted usinga lentalo applicator. In this manner, it is hoped that the remainingspaces between the gutta percha points and the root canal can be filledwith the antiseptic paste or resin. In addition, it is hoped that theepoxy-based resin will help to seal the root canal.

[0008] One of the drawbacks of using conventional pastes or resins isthat such materials tend to be hydrophobic. This renders such materialssomewhat incompatible with dental tissues within the root canal, whichare highly mineralized, somewhat moist and therefore extremelyhydrophilic. The hydrophilic nature of the root canal environmentinhibits wetting and adhesion of the root canal by hydrophobicmaterials. As a result, conventional antiseptic pastes and epoxy-basedresins actually form a poor seal between the gutta percha points and thewalls of the root canal, thus potentially providing access for microbesand infection.

[0009] A further problem of conventional antiseptic pastes andepoxy-based endodontic sealing resins are their inability to adequatelypenetrate into, wet and seal the lateral canals which extend laterallyfrom the root canal into the root of the tooth. Occasionally, theinability to seal the lateral fissures using conventional pastes and/orepoxy-based resins creates one more place where microbes may establish abeach head and be capable of festering over time.

[0010] In addition to the inability of the antiseptic pastes orepoxy-based resins to adequately adhere to and seal the root canals andlateral fissures, another problem relates to the inability to evacuateall air bubbles or pockets from the root canal during placement of thegutta percha points and associated pastes or resins. As the gutta perchapoint coated with pastes or resins is packed into the root canal, or assealers are worked in with a lentalo applicator, upper portions of thegutta percha or sealer can seal against the root canal wall, thustrapping air between the coronal portion and the root canal apex.Failure to remove such air pockets creates an area where subsequentinfection can fester. Although gutta percha is highly radiopaque, evenif the dentist can observe whether or not the root canal spaces havebeen adequately filled, the task of removing the packed materials andrepeating the procedure is time consuming, expensive, and uncomfortablefor the patient. Moreover, many sealer pastes are only moderatelyradiopaque and include silver powder, which makes the root canal toodark.

[0011] Lateral condensation using gutta percha is typically notsufficient to force the highly viscous pastes, gutta percha, or resinsinto the lateral canals. Merely pushing against the top portion of thegutta percha does not exert very much force on the flowable pastes orresins, since pressurized fluids can escape around the space between thegutta percha, lateral condensation instrument, and the root canal ratherthan being forced into the lateral canals or other areas occupied by airbubbles or pockets.

[0012] Finally, in the case where nonpolymerizable pastes, such as zincoxide/eugenol are used, the chemistries of such materials can interferewith the ability of subsequently placed prosthetic filling materials tochemically bond or adhere to the tooth.

[0013] In short, it would be an improvement of the art of endodonticprocedures to provide compositions and methods which improved theability of an endodontic sealing material to penetrate, wet, adhere andseal to the dental tissues surrounding or defining the root canals.

[0014] It would be an additional improvement in the art to providecompositions and a methods that provided for a more thorough evacuationof air bubbles or air pockets within the root canal, as well asincluding lateral spaces or canals connected to or in communication withthe main root canal branches.

[0015] It would also be an improvement in the art to providecompositions and methods which yielded a filled root canal in which thesealing material did not interfere with the ability of a subsequentlyplaced composite resin material to bond or adhere to the tooth.

[0016] It would be a further advancement in the art if such compositionsand methods provided for the ability to allow for variable curing timessuch as faster or slower curing, to account for variations in difficultyand success that may be experienced by a dental practitioner.

[0017] It would yet be an improvement in the art if such compositionscould also be light cured so as to reduce the time a patient must waituntil the root canal sealing material was sufficiently cured to permitsubsequent filling of the remainder of the tooth with a compositefilling material.

[0018] Such compositions and methods for more effectively filling andsealing a root canal and providing a bonding surface are disclosed andclaimed herein.

SUMMARY AND OBJECTS OF THE INVENTION

[0019] The present invention encompasses adhesive resins for use infilling and/or sealing a root canal during an endodontic procedure, aswell as procedures for filling and sealing a root canal. The adhesivesealing and filling resins according to the present invention include acomponent that is compatible with a hydrophilic environment and thatallows the resin to wet, penetrate and adhere to the dental tissuesurrounding the root canal. In addition, such resins are better able topenetrate into and seal the lateral canals that often extend from themain root canal branches. In order to assist such sealing, improvedmethods for applying a pressure to the sealing and filling resins arealso disclosed.

[0020] The present invention encompasses adhesive resins for use infilling and/or sealing a root canal during an endodontic procedure, aswell as procedures that employ such compositions. The adhesive sealingand filling resins according to the present invention include acomponent that is compatible with a hydrophilic environment and thatallows the resin to wet, penetrate and adhere to the dental tissuesurrounding the root canal. In addition, such resins are better able topenetrate into and seal the lateral canals that often extend from themain root canal branches. In order to assist such sealing, improvedmethods for applying a pressure to the sealing and filling resins arealso disclosed.

[0021] The adhesive sealing and filling compositions of the presentinvention include one or more polymerizable methacrylate monomers,preferably including an oxyphosphorus constituent for better adhesion, aradio opacifying agent, and one or more types of polymerizationinitiators. The composition may also include other additives such asdiluent or complementary monomers, fillers, antimicrobial agents,plasticizers, solvents and the like.

[0022] The adhesive sealing and filling compositions of the presentinvention include one or more polymerizable methacrylate monomers,preferably including an oxyphosphorus constituent for better adhesion, aradio opacifying agent, and one or more types of polymerizationinitiators. The composition may also include other additives such asdiluent or complementary monomers, fillers, antimicrobial agents,plasticizers, solvents and the like.

[0023] An example of an adhesive methacrylate resin within the scope ofthe invention is bis-glycidyl dimethacrylate phosphate. An example of aradio opacifying agent according to the present invention is bismuthchloride. An example of a suitable diluent monomer is urethanedimethacrylate. Examples of polymerization initiators include chemicalinitiators, such as peroxides and amines, and photoinitiators, such ascamphor quinone. Because it is typically impossible to completely cure apolymerizable resin using photo initiation as the sole means to initiatepolymerization, particularly all the way down to the apex of the rootcanal, it will typically be advantageous to include a chemical initiatorso as to ensure complete curing of the polymerizable monomer over time.

[0024] In a preferred embodiment, the chemical initiator will beselected and included in an amount so as to provide sufficient time fora dental practitioner to properly place the composition within the rootcanal and ensure good penetration into the lateral canals. In mostcases, it will be advantageous to include a chemical curing agent thatcauses the polymerizable resin to cure within a time period of fromabout 15 minutes to about 2 hours, more preferably from about 30 minutesto about one hour.

[0025] In the event that the dentist determines that the endodonticsealing resin has been properly placed, the dentist can then rapidlycure the upper portion of the resin by means of the inclusion of aphotoinitiator and the application of curing radiation, such as lightgenerated by a conventional dental curing lamp. In this way, the dentistcan cure the top few millimeters of endodontic sealing resin by means ofthe curing lamp so as to provide a hardened upper surface to which acomposite filling material can be chemically bonded or adhered. Thisgreatly speeds up the time in which a dentist can complete theendodontic procedure.

[0026] In the case of resins or sealers that are only chemically cured,the dentist must ensure adequate curing and solidification prior toplacing a composite resin on top of the sealing resin. In some cases,the patient must sit in the dental chair for half an hour, to an hour ormore, wasting both the dentist's and the patient's time. In many cases,the dentist will simply place a temporary filling material over theuncured resin and send the patient home with the result being thepatient must return for a follow-up visit in which the dentist removesthe temporary filling material and replaces it with the finalrestorative material.

[0027] Embodiments that include “dual cure” compositions (i.e.,compositions that are capable of both chemical and light cure) provide atremendous advantage over single cure vresins. Although such dual curecapability has been available for luting cements, it has never beenavailable for root canal sealing or filling materials. The chemical cureproperties provide the aforementioned window of time to account forvariations in procedure difficulty and success, while the light cureproperties provide for almost immediate curing of the top layer byphotoinitiated curing once it has been determined that the sealing orfilling material has been properly placed. This provides a tremendousadvantage for both the dentist and the patient because it obviates theneed for a patient to either sit in the dental chair wasting time whilethe resin cures or else having to make a return visit to receive thefinal filling material. Another advantage is that the resins chemicallycure in a relatively short period of time compared to conventionalsealers, thus minimizing the tendency of monomers to leach into thesurrounding tissue.

[0028] In another aspect of the invention, the adhesive resins areplaced within the root canal by means of a narrow cannula or syringe tipdevice attached to a high pressure hydraulic device or system. Due tothe viscosity of the mixed polymerizable resins or non resinous pastessuch as zinc oxide pastes, coupled with the small size of typical rootcanals, it is difficult to express sealing resins or pastes throughcannulas or syringe tips capable of entering into a root canal. For thisreason, the inventive methods according to the present inventioncontemplate the use of high pressure syringes or other hydraulicdevices, such as those disclosed in copending U.S. application Ser. No.09/467,419, filed Dec. 20, 1999, now issued U.S. Pat. No. 6,425,885, andpresently assigned to Ultradent Products, Inc. For purposes ofdisclosure, the foregoing U.S. patent and application are incorporatedherein by specific reference.

[0029] In a preferred method for placing adhesive resins within a rootcanal, the apex of the root canal is first sealed using a gutta perchacone. In order to ensure that the apex has been adequately sealed, a“tug back” seal is formed. That is, the gutta percha cone is firstinserted and then removed. If it can be removed with little or no force,the gutta percha point is trimmed to yield a larger diameter tip andreinserted into the apex. This process is repeated until there is “tugback,” thus indicating that the fit between the gutta percha point andthe apex is sufficiently tight to adequately seal the apex and preventflow of sealing or filling material therethrough into the surroundingbone tissue.

[0030] After sealing the apex, the sealing or filling resin is insertedinto the root canal using a narrow cannula tip. The cannula tip isplaced within the root canal near the apex and slowly raised as the rootcanal is filled with resin, thus minimizing or eliminating the formationof air pockets or bubbles as the sealing or filling resin isprogressively placed within the root canal. This procedure greatlyimproves the ability of the resin to initially purge most or all of theair from within the root canal compared to simply dipping a gutta perchapoint in the resin and stuffing the point into the root canal, orspinning the material with lentalo applicators, as is typically doneusing conventional methods.

[0031] In order to further ensure that the endodontic sealing resinpenetrates and seals every space, irregularity, or lateral canal of theroot canal, it may be advantageous to apply pressure to the resin afterit has been initially placed within the root canal. This may beaccomplished, for example, by inserting a plunger of complimentary sizeinto the hole previously bored through the crown of the tooth. Theplunger will typically include a plunger rod and a resilient plungerplug, such as a plug made of gutta percha material. In a preferredmethod for forming a plunger, excess gutta percha material trimmed froma gutta percha cone used to fill a root canal is wrapped around the endof a stiff metallic wire or plunger rod. The wire and gutta percha arethen placed through the hole of the tooth. The wire is heated, whichmomentarily causes the gutta percha to melt and coalesce together, thusforming a resilient plunger plug having a size complementary to the holein the tooth.

[0032] Inward pressure of the plunger from the crown toward the apex ofthe root canal exerts pressure on the resinous sealing material, thusforcing the material into the cracks, crevices and lateral canals of theroot canal. Because the resilient gutta percha plug seals against thewalls defining the hole through the crown of the tooth, the resinousmaterial is not able to squeeze out between the tooth and the guttapercha plug but is instead forced into the aforementioned spaces,crevices or canals. In this manner, the resinous sealing or fillingmaterial is able to substantially form a hermetic seal of the rootcanal.

[0033] Providing a more complete seal of the root canal greatlyincreases the ability of the sealed root canal to resist the ingress offluids into the root canal. Such fluids, if allowed to enter a rootcanal, may introduce microbes capable of infecting the tooth andsurrounding bone. In improving the ability of the resinous sealingmaterial to actually seal the root canal, including lateral canals andother crevices typically hard to fill, the inventive compositions andmethods provide a tremendous advantage over conventional compositionsand methods in yielding a tooth that is more resistant to microbialleakage.

[0034] In view of the foregoing, it is an object of the invention toprovide compositions and methods which improve the ability of anendodontic sealing material to wet, adhere and seal to the dental tissuesurrounding or defining the root canals.

[0035] It is an additional object of the invention to providecompositions and methods that provide for a more thorough evacuation ofair bubbles or air pockets within the root canal, as well as lateralspaces or canals connected to, or in communication with, the main rootcanal branches.

[0036] It is also an object of the invention to provide compositions andmethods which yield a filled root canal having a material to which asubsequent composite resin material can chemically bond or adhere.

[0037] It is a further object of the invention to provide compositionsand methods which provide for variable curing times, such as faster orslower curing, to account for variations in difficulty and success thatmay be experienced by a dental practitioner.

[0038] Additional features and advantages of the invention will be setforth in the description which follows, and in part will be obvious fromthe description, or may be learned by the practice of the invention. Thefeatures and advantages of the invention may be realized and obtained bymeans of the instruments and combinations particularly pointed out inthe appended claims. These and other features of the present inventionwill become more fully apparent from the following description andappended claims, or may be learned by the practice of the invention asset forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to describe the manner in which the above recited andother advantages and features of the invention can be obtained, a moreparticular description of the invention briefly described above will berendered by reference to specific embodiments thereof which areillustrated in the appended drawings. Understanding that these drawingsdepict only typical embodiments of the invention and are not thereforeto be considered to be limiting of its scope, the invention will bedescribed and explained with additional specificity and detail throughthe use of the accompanying drawings, in which:

[0040]FIG. 1 is a cross sectional view of a tooth showing a root canalwith a gutta percha cone inserted into the apex so as to seal the apexand provide a fluid-tight seal;

[0041]FIG. 2 is a cross sectional view of the tooth of FIG. 1 in which asmall diameter cannula device has been inserted within the root canalfor the purpose of filling the root canal with an endodontic sealing orfilling resin;

[0042]FIG. 3 is a cross sectional view of the tooth of FIGS. 1 and 2after the root canal has been filled with an endodontic sealing orfilling resin;

[0043]FIG. 4A is a cross sectional view of the tooth of FIG. 3 in whicha portion of a gutta percha cone has been wrapped around the end of awire preparatory to heating and melting the gutta percha to form asyringe-like plunger to be inserted into the tooth;

[0044]FIG. 4B is a cross sectional view of the tooth of FIG. 4A in whichthe gutta percha has been melted and conformed to the diameter of theopening in the tooth so as to form a plunger-like device used to exertpressure onto the endodontic sealing or filling resin to force the resininto the lateral microfissures in communication with the root canal; and

[0045]FIG. 5 is a cross sectional view of a tooth in which theendodontic sealing or filling resin within the root canal is beingpartially cured using a curing lamp preparatory to placing a finalfilling material and/or crown to seal the root canal.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0046] I. Introduction.

[0047] The present invention is directed to polymerizable resins usedfill a root canal during endodontic procedures. The invention alsorelated to improved procedures for placing the inventive sealing orfilling resins, as well as conventional resins or pastes, within a rootcanal. To provide better compatibility with the hydrophilic environmentwithin a tooth, the adhesive sealing or filling resins advantageouslyinclude a component that is compatible with hydrophilic and mineralizeddental tissues. Increased hydrophilic compatibility facilitates wettingof the dental tissue, enables penetration of the sealing material withingaps, spaces and lateral canals associated with the root canal, andpromotes penetration into the dentinal tubules and, hence, superioradhesion to the dental tissue surrounding the root canal.

[0048] Sealing or filling resins and other flowable sealing or fillingmaterials may optionally be placed within a root canal by means ofpressurized hydraulic systems or devices able to deliver viscous fluidsthrough narrow cannulas placed within the root canal. Once placed, thesealing resins or other materials are advantageously forced underpressure into the lateral canals associated with the main root canalbranches, thus providing a much better seal of the root canal. This maybe accomplished by means of a mini syringe-like plunger or like devicethat works in conjunction with a customized bore through the crown ofthe tooth.

[0049] The adhesive sealing or filling resins within the scope of thepresent invention typically include one or more monomers that promoteadhesion, such as methacrylate monomers having an oxyphosphorusconstituent, a radio opacifying agent, and one or more types ofpolymerization initiators. The term “radiopaque” refers to materialsthat allow the composition to be more easily seen using an X-ray. Thecomposition may also include other additives such as diluent monomers,fillers, antimicrobial agents, plasticizers, solvents and the like.

[0050] The compositions and methods are effective in reliably sealingthe root canal from the ingress of fluids and bacteria from the crownand/or periodontal tissue. This helps to ensure the mechanical integrityof the treated tooth. Equally or more important, it protects surroundingbone from being infected by bacteria that may have otherwise infectedthe treated tooth. In one embodiment, the sealing or filling resins maybe dual curable, that is, curable both chemically and by irradiationwith light energy. This gives the dentist greater control over the timeit takes to provide sufficient curing of the sealing or filling resin topermit placement of a final filling material or prosthetic covering.

[0051] II. Endodontic Sealing or Filling Compositions.

[0052] A wide variety of polymerizable monomers, radiopaque materials,initiators, and other components may be used within the inventiveendodontic sealing or filling compositions within the scope of theinvention, including those disclosed in U.S. Pat. No. 6,071,528 toJensen and presently assigned to Ultradent Products, Inc. located inSouth Jordan, Utah. For purposes of disclosure, the foregoing patent isincorporated herein by specific reference.

[0053] The compositions within the scope of the invention can bechemically curable, photo curable, or dual cure. In the case of chemicaland dual cure sealing or filling compositions it will typically benecessary to provide a two-part (or multi-part) composition that ismixed by the dentist just prior to use. One part will include all theconstituents of the resin sealing or filling together with one half ofthe chemical cure system (e.g., a peroxide compound), while another partwill include all the constituents of the resin sealing with the otherhalf of the chemical cure system (e.g., an amino compound). In the caseof a photocured sealing or filling composition, the polymerizable resinwill advantageously be stable in the presence of the photoinitiatorabsent the application of radiant energy.

[0054] In the case of chemically cured systems, the final endodonticsealing or filling composition, upon mixing the multiple parts together,will preferably cure within a time period of about 15 minutes to about 2hours, more preferably in a range of about 30 minutes to about one hour.

[0055] On the other hand, in the case of a photo cured system, includingdual cure systems, irradiating the sealing or filling composition withradiant energy, such as from an ultraviolet curing lamp, can effect muchmore rapid curing than chemical cure alone. The upper 1-3 mm of sealingor filling material within the root canal can typically be photo curedin a period of time of from about 10 seconds to about one minute.

[0056] A. Adhesion and Diluent Monomers.

[0057] The polymerizable sealing or filling compositions according tothe invention include at least one adhesion monomer that is at leastpartially hydrophilic and/or includes constituents which make anotherwise hydrophobic resin more adhesive to dental tissue. The adhesionmonomers within the scope of the invention may include any monomer thatyields a composition that is capable of wetting and penetrating into thedentinal tubules. General examples include a wide range of acrylates,methacrylates, alkylhydroxy methacrylates, alkylamino methacrylates, andderivatives thereof. More specific examples of adhesion monomers includeglycidyl dimethacrylate, 2-hydroxy ethyl methacrylate, 3-hydroxy propylmethacrylate, 4-hydroxy butyl methacrylate, triethylene glycoldimethacrylate, and polyethylene glycol dimethacrylate.

[0058] In a most preferred embodiment, the adhesion monomer may includean oxyphosphorus alkyl methacrylate. The currently preferredoxyphosphorus alkyl methacrylate comprises bis glycerol dimethacrylatephosphate. Examples of other oxyphosphorus alkyl methacrylates withinthe scope of the invention include bis 2-hydroxy ethyl methacrylatephosphate, phosphate ester of p-hydroxyphenyl methacrylamide, phosphateester of 3-hydroxy propyl methacrylate, and phosphate ester of 4-hydroxybutyl methacrylate. Notwithstanding the foregoing examples, theoxyphosphorus alkyl methacrylate can be any alkyl methacrylate having anoxyphosphorus group or phosphorus acid group selected from the groupconsisting of:

[0059] wherein R is an alkyl or aryl.

[0060] The oxyphosphorus group not only tends to increase theadhesiveness of the resin compared to analogous compounds lacking thisadded constituent, but it also increases the water solubility, orrelative hydrophilicity, of the resulting resin. In an informalcomparison of the relative water solubilities of glycidyl dimethacrylateand bis glycerol dimethacrylate phosphate, the latter was found to beconsiderably more water soluble compared to the former. On this basis,it was presumed that the addition of the oxyphosphorus group increasedthe hydrophilicity of the resulting compound compared to the originalcompound.

[0061] In addition to the adhesion monomer, the compositions accordingto the invention may include one or more additional (or diluent)monomers to achieve the desired properties of initial flowability,curability, and final cured strength and hardness. In the case where theadhesion monomer includes an oxyphosphorus alkyl methacrylate, thediluent monomer may include any of the non oxyphosphorus monomers listedabove. In addition, monomers that are hydrophobic yet suitable asdiluent monomers include urethane dimethacrylate, p-hydroxyphenylmethacrylamide, butanediol dimethacrylate, and bisphenol-A-diglycidyldimethacrylate (“Bis-GMA”).

[0062] The adhesion monomers are preferably included in a concentrationranging from about 0.01% to about 90% by weight of the composition, morepreferably from about 0.5% to about 30% by weight, and most preferablyfrom about 1% to about 10% by weight of the composition.

[0063] The diluent monomers may be included in amounts of up to about95% by weight of the composition, preferably in a range from about 5% toabout 80%, and more preferably in a range from about 10% to about 70% byweight of the composition.

[0064] B. Initiators.

[0065] Initiators are provided in the composition to inducepolymerization of the monomer. The initiators or curing agents mayinclude radiant energy polymerization initiators with or without anappropriate organic amine additive or a chemical initiator with anappropriate organic amine additive.

[0066] 1. Photoinitiators.

[0067] Examples of photoinitiators within the scope of the inventioninclude camphor quinone, benzoin methyl ether,2-hydroxy-2-methyl-1-phenyl-1-propanone, diphenyl 2,4,6-trimethylbenzoylphosphine oxide, benzoin ethyl ether, benzophenone, 9,10-anthraquinone,and derivatives thereof.

[0068] Photoinitiators are preferably included in an amount in a rangefrom about 0.05% to about 5% by weight of the composition, morepreferably in a range from about 0.1% to about 2% by weight, and mostpreferably in a range from about 0.2% to about 1% by weight of thecomposition.

[0069] 2. Chemical Initiators.

[0070] Examples of chemical initiators include a wide range ofperoxides, other per components, and other free radical generators. Atwo-part chemical curing system typically includes a peroxideconstituent in one part and an amino compound in another. Exemplaryperoxides include benzoyl peroxide, 2-butanone peroxide, lauroylperoxide and tert-butyl peroxide. Examples of amino compounds includedimethylamino ethyl methacrylate, triethyl amine, 2-dimethylaminoethanol, diethylamino ethyl methacrylate, trihexyl amine,N,N-dimethyl-p-toluidine, N-methylethanolamine, 2,2′(p-tolyimino)diethanol, and derivatives thereof.

[0071] In a preferred embodiment, the chemical initiator will beselected and included in an amount so as to provide sufficient time toallow the dentist or dental practitioner to have sufficient time toplace the resinous sealing or filling material into the root canal andcause it to flow into the lateral canals. In other words, once mixed,the curing time will be sufficiently long so as to allow the dentist tocarry out a desired sealing and/or filling procedure. On the other hand,unlike conventional sealers, which often cure very slowly, sometimesover a period of one or more days, the sealing and filling materials ofthe invention are typically formulated so that they will cure morerapidly, typically in 2 hours or less in order to inhibit or avoidleaching of the polymerizable monomer into the surrounding dentaltissue.

[0072] In most cases, it will be advantageous to include a chemicalcuring agent in order for the polymerizable resin to cure within a timeperiod of about 20 minutes to about 2 hours, more preferably from about30 minutes to about one hour. Such time periods generally providesufficient time to determine whether or not the sealing material hasbeen properly placed. If not, the uncured resin can be removed andreplaced with new resin in a follow-up procedure.

[0073] Chemical initiators are preferably included in an amount in arange from about 0.01% to about 5% by weight of the composition, morepreferably in a range from about 0.05% to about 2% by weight, and mostpreferably in a range from about 0.1% to about 1% by weight of thecomposition.

[0074] C. Radiopaque Fillers.

[0075] Radiopaque fillers are advantageously included in order toprovide the ability of the dentist to X-ray and determine how well theendodontic resin has penetrated into and filled the root canal,including the lateral canals. Examples of fillers that can provideincreased radio opacity include bismuth salts such as bismuth chloride,silver and silver salts such as silver chloride, barium salts such asbarium sulfate or barium chloride, tungsten salts, titanium dioxide, andstrontium salts such as strontium sulfate and strontium chloride. Theseand other fillers such as silicon dioxide and calcium phosphate tribasicmay also be used to minimize polymerization shrinkage and the total heatpotential of polymerization.

[0076] It is within the scope of the invention to include fillers in anamount of up to about 85% by weight of the composition, more preferablyin a range from about 2% to about 70% by weight, and most preferably ina range from about 5% to about 50% by weight of the composition.

[0077] D. Antimicrobial Agents.

[0078] The sealing or filling compositions may optionally include one ormore antimicrobial agents to assist in cleansing and sterilizing theroot canal and to prevent later infection. Examples of suitableantibacterial agents include organohalogens, antibiotics, alkali metalhydroxides, alkaline earth metal oxides, and alkaline earth metalhydroxides.

[0079] Examples of antibacterial organohalogens include1,1′-hexamethylene bis(5(p-chlorophenyl)biguanide), cetyl pyridiniumchloride, benzalkonium chloride, and cetyl pyridinium bromide.

[0080] Examples of suitable antibiotics include: 4′sulfamoylsulfanilanilide,3-amino-6-(2-(5-nitro-2-furyl)vinyl)pyridazine, trans-pseudomonic acid,xanthomycin, alpha-amino-p-toluene sulfonamide, alpha-azido benzylpenicillin, penicillin O, penicillin N, monopropionyl erthromycin, anderythromycin 9(O-((2-methoxy ethoxy)methyl)oxime.

[0081] Examples of suitable alkali metal hydroxides include sodiumhydroxide and lithium hydroxide.

[0082] Examples of suitable alkaline earth metal oxides include calciumoxide, magnesium oxide, barium oxide, and strontium oxide.

[0083] Examples of suitable alkaline earth metal hydroxides includecalcium hydroxide, magnesium hydroxide, barium hydroxide, and strontiumhydroxide.

[0084] A more preferred antimicrobial agent is calcium hydroxide sincecalcium hydroxide not only kills microorganisms but is chemicallycompatible with dental tissue. The antimicrobial agent may be includedin an amount in a range from about 0.001% to about 30% by weight of thecomposition, preferably in a range from about 0.005% to about 10% byweight, and most preferably in a range from about 0.01% to about 5% byweight of the composition.

[0085] E. Other Additives.

[0086] It is certainly within the scope of the invention to includeother additives or adjuvents as desired in order to impart a desiredproperty, such as less or non radiopaque fillers, solvents, dyes orplasticizers. For example, silica may be included in order to imparthardness in the case where a sealing filler material is desired. Keepingthe silica content low, however, improves the ability to later drill outa portion of the cured material if desired, such as to place a postduring a crown restoration.

[0087] III. Methods for Sealing a Root Canal with Endodontic Resins.

[0088] An exemplary method for placing and then curing an endodonticsealing or filling resin within a root canal is illustrated in FIGS.1-5. FIG. 1 depicts a tooth 10 that has been subjected to a root canalprocedure. The tooth 10 includes a pair of root canals 12, each of whichterminates at an apex 14 that extends through the bottom of the root 16.An opening 18 through the crown of the tooth provides access to the rootcanals 12, thereby permitting endodontic tools (not shown) to beinserted into the root canals 12. A gutta percha cone 20 has beeninserted into each opening 18 in order to seal the apex 14 of each rootcanal 12 to prevent flow of sealing material into the surrounding bonetissue.

[0089] In order to ensure that the gutta percha cone 20 forms a reliableseal within the apex 14, a procedure involving “tug back” is preferablyperformed. In this procedure, the gutta percha cone is inserted andremoved, sometimes more than one time, to determine how much force isneeded to remove the gutta percha cone. If it can be removed with littleor no force, there is insufficient tug back, and the gutta percha pointis trimmed to yield a larger diameter tip and reinserted into the apex.This process is repeated until there is sufficient tug back, orresistance, felt by the dentist or dental practitioner. One of ordinaryskill in the art of endodontics will know when there is sufficient tugback to confirm an adequate seal of the apex 14 by the gutta percha cone20. Sufficient tug back indicates that the fit between the gutta perchacone and the apex is sufficiently tight to adequately seal the apex andprevent flow of sealing or filling material therethrough into thesurrounding bone tissue.

[0090] In addition to the root canals 12, lateral canals 22 extend fromthe root canals 12 and provide communication between the root canals 12and the surrounding periodontal tissue of the lower portion of the tooth10. The lateral canals 22 are particularly difficult to seal usingconventional compositions and methods. The inventive compositions andmethods, however, facilitate penetration of resinous sealing or fillingmaterial into the lateral canals 22.

[0091] In a preferred method for placing a resinous sealing or fillingmaterial within a root canal, FIG. 2 depicts a syringe tip 24 having anarrow diameter cannula 26 attached to an enlarged portion 28 of thesyringe tip 24 used to insert sealing or filling material into the rootcanal 12. Due to the narrow opening of the cannula 26, and becausetypical sealing or filling materials often sufficiently viscous thatthey may not readily pass through the cannula 26, it will generally beadvantageous for the syringe tip 24 to be attached to a high pressurehydraulic injection system (not shown). Examples of high pressurehydraulic syringes or systems are set forth in the aforementionedcopending U.S. application Ser. No. 09/467,419, filed Dec. 20, 1999, nowU.S. Pat. No. 6,425,885. Examples of narrow cannulas sized for entryinto a root canal are set forth in U.S. Pat. No. 6,079,979, which isassigned to Ultradent Products, Inc. For purposes of disclosinghydraulic pressurizing systems and cannulas sized to fit within a rootcanal, the foregoing patent application and patent are incorporatedherein by specific reference.

[0092] The tip of the cannula 26 is initially placed within the rootcanal 12 near the apex 14, and sealing or filling material (not shown)is expressed therefrom into the root canal 12. As the resinous materialbegins and continues to fill up the root canal 12, the cannula 26 isslowly raised or withdrawn from the root canal 12. This manner offilling the root canal 12 with resinous material minimizes or eliminatesthe formation of air pockets or bubbles as the resin is progressivelyplaced within the root canal 12. This procedure greatly improves theability of the resin to initially purge most or all of the air fromwithin the root canal 12 compared to simply dipping a gutta percha pointin the resin and stuffing the point into a root canal, as isconventionally done.

[0093]FIG. 3 depicts a tooth 10 into which a resinous sealing or fillingmaterial 30 has been successfully placed within the root canals 12, withlittle or no formation of air pockets. Even so, initial placement of theresin 30 in this manner does not typically result in complete filling ofthe lateral canals 22. To ensure that the endodontic sealing or fillingmaterial 30 has penetrated into and sealed every space, irregularity orlateral canal 22 of the root canal 12, it may be advantageous to applyadditional pressure to the resin 30 after it has been initially placedwithin the root canals 12. In one embodiment, additional pressure may beapplied by inserting a plunger-like device into a hole 32 through thecrown 33 of the tooth 10 that is initially made to provide access to theroot canals 12 during the root canal procedure. FIGS. 4A and 4Billustrate this optional procedure.

[0094] In order for the plunger-like device to work in applyingsufficient pressure so that the filling or sealing resin 30 is forcedinto the lateral canals 22, it will be advantageous to provide aresilient plug-like material that is able to conform to and seal againstthe inner wall 34 of the tooth 10 defining the hole 32. The resilientplug-like material will preferably have a diameter that is complementaryto the diameter of the hole 32. Although the plunger-like device mayinclude any resilient plug-like material, in a presently preferredmethod, the resilient plug-like material is formed from excess guttapercha material that is trimmed off of the gutta percha cone 20.

[0095] As more clearly depicted in FIG. 4A, a length of excess guttapercha is wrapped around a wire 36 to form a gutta percha wrap or bundle38 to form a plunger 40. Heat is then applied to the wire 36 in order tocause the gutta percha wrap or bundle 38 to melt slightly so that itcoalesces together to form the resilient plug-like material. While thegutta percha bundle 38 is in a plastic state, the plunger 40 is placedinto the hole 32 of the tooth 10 in order to allow the gutta perchabundle to flow or otherwise conform to the size and shape of the hole32.

[0096] As shown in FIG. 4B, once the gutta percha bundle 38 hascoalesced together and conformed to the shape of the hole 32, it yieldsa plunger 40 having a gutta percha plug 42 on the end thereof. The guttapercha plug 42 is allowed to cool and thereby adhere to the wire 36.Thereafter, the wire 36 and gutta percha plug 42 yield a plunger 40 thatcan be used to exert pressure on the resinous sealing or fillingmaterial 30 in order to force it to flow into the cracks, crevices andlateral canals 22 that may extend from the root canal 12. In addition,pressure applied by the plunger 40 may also assist the resin 30 to flowinto the dentinal tubules in order to promote better adhesion betweenthe resin 30 and the dental tissue surrounding the root canal 12.

[0097] As depicted in FIG. 4B, force applied to the plunger 40 in adirection from the crown of the tooth 10 towards the apex 14 of the rootcanals 12. Force may be applied to the plunger 40 manually or by meansof pliers or other gripping tools. Pressure is maintained on theresinous sealing or filling material 30 because the elastomeric plug 42seals against the inner wall 34 defining the hole 32 through the crown33 of the tooth 10. Because of this, the resinous material 30 is notable to squeeze out in appreciable amounts between the tooth wall 34 andthe resilient plug 42. Instead, the pressure exerted onto the resinousmaterial 30 forces it into the aforementioned spaces, crevices orcanals. In this manner, the resinous sealing material 30 is able to forma substantially hermetic seal of the root canals 12.

[0098] Although FIGS. 4A and 4B depict a preferred method for forming asuitable plunger 40 for use in applying pressure to the resinous sealingor filling material 30, it should be understood that plunger-likedevices or other pressurizing means would be within the scope of theinvention. In view of the present disclosure, one of ordinary skillcould design other pressuring means that would work to apply pressure tothe resin 30. For example, in place of gutta percha, the plunger 42 maycomprise any resilient or elastomeric material that can seal against theinner wall of the hole 32 through the crown. Examples include othernatural rubbers, silicone rubbers and other synthetic rubbers orelastomers.

[0099] J Providing a more complete seal of the root canal 12 greatlyincreases the ability of the sealed root canals 12 to resist the ingressof fluids therein. Such fluids may enter the root canals 12, forexample, through fissures in the crown and/or periodontal tissue. Suchfluids, if allowed to enter the root canals 12, may carry microbescapable of attacking and decaying the dental tissue surrounding the rootcanals 12, thus compromising the mechanical integrity of the dead tooth10 and, more importantly, potentially infecting surrounding teeth. Inimproving the ability of the resinous material 30 to more effectivelyseal the root canals 12, including the lateral canals 22 and othercrevices that are typically hard to fill, the inventive compositions andmethods provide a tremendous advantage over conventional compositionsand methods in yielding a tooth that is more resistant to microbialattack.

[0100] As set forth above, the resinous sealing or filling materials maybe chemically cured, photo cured or dual cured. In a preferredembodiment, the compositions will be dual cured. That is, they willpreferably be cured both by means of a chemical curing agent and by theapplication of radiant energy. Because photo curing is only capable ofcuring the top layers of the resinous sealing or filling material 30,but is incapable of sealing all the way down to the apex 14 of the rootcanal 12, photo curing alone is typically insufficient to provide anadequately cured resinous material 30 throughout the entire length ofthe root canal 12. For this reason, it will typically be necessary toprovide chemical curing of the resinous material 30 in order to ensurethat resinous material cures completely throughout the entire root canal12 and associate lateral canals 22, crevices and spaces.

[0101] Nevertheless, because chemically cured sealing or fillingmaterials preferably cure slowly over time (e.g., between 20 minutes and2 hours) so as to provide the dentist with adequate time to mix and thenplace the sealing or filling material, it may be desirable to speed upthe curing process once proper placement of the resinous sealingmaterial has been verified. Once a dentist or other dental practitioneris sufficiently confident that the resinous material has been adequatelyplaced, it may be desirable to speed up the curing process, at least onthe surface or upper portion 44 of the resinous material 30, in order toprovide a hardened surface 46 to which a composite material (not shown)can be bonded.

[0102] As depicted in FIG. 5, a curing lamp 50 that emits radiant energy52, such as ultraviolet radiation, can be used to cure the top or upperportion 44 of a dual cure sealing or filling material. The photo curedportion 44 will typically only extend partially down the root canal 12while the remaining portion 48 will extend all the way to the apex 14 ofthe root canal. The hardened upper portion 44 of the resinous materialprovides a hardened surface 46 to which a composite filling material(not shown) can immediately be chemically bonded or adhered. This allowsthe dentist to rapidly complete the endodontic process and eliminatesthe need for the patient to either sit in the dental chair while theresinous material chemically cures or make an appointment for a followup visit to receive the final filling material.

[0103] It should be understood that the compositions and proceduresaccording to the present invention may be used with or without guttapercha points. One advantage of using gutta percha points is that theycan be used to seal the apex 14 with each root canal 12 prior to placingthe resinous sealing material therein. This helps to prevent incursionof the sealing or filling material into the surrounding bone tissue.Another advantage of a gutta percha point is that it provides a paththrough which a hole can be drilled through the sealed root canalwithout compromising the surrounding cured sealing or filling material.Such holes are referred to as “channel holes” or “post channel holes”.Channel holes may be drilled, for example, in order to place reinforcingposts (not shown) down the root canal in the case of a relatively weaktooth. Posts are also used when attaching a prosthetic crown to a tooth.

[0104] On the other hand, the resinous sealing or filling materialsaccording to the present invention will typically be softer than typicalcomposite materials and may be easily drilled in many cases. Because ofthis, it may be unnecessary to utilize gutta percha points to facilitatethe formation of channel holes through the root canal if needed.

[0105] Another advantage of the compositions and methods according tothe present invention is that they provide a bonding surface to which acomposite material, such as materials that include Bis-GMA, can form achemical or adhesive bond. Prior art antiseptic pastes, such as zincoxide/eugenol or calcium hydroxide mixed with iodoform, do not provide abonding surface to which composites can bond. Such materials aregenerally inert and relatively soft, thus providing neither chemical normechanical bonding possibilities. Moreover, to the extent that suchmaterials become interposed between the composite material and thetooth, they may inhibit bonding between the composite material and thetooth. In the case of amalgam, providing a hardened sealing or fillingmaterial, at least on the surface of the sealed root canal, willfacilitate placement of the amalgam. Because of the soft nature of theprior antiseptic pastes, it was always necessary to utilize a post inorder to provide a mechanical attachment surface to which a composite oramalgam filling material could attach. The photocurable sealing orfilling materials according to the invention reduce or eliminate theneed for such posts.

[0106] The resinous sealing or filling materials according to thepresent invention are also safer compared to prior art sealers, such as26H or 26 Plus sold by Dentsply, which are known to leach formaldehydeinto the surrounding dental tissue.

IV. EXAMPLES OF THE PREFERRED EMBODIMENTS

[0107] Several examples of the present invention are presented as merelyillustrative of some embodiments of the present invention. Theseexamples are not to be construed as limiting the spirit and scope of theinvention. Examples written in past tense refer to actual compositionsthat have been made, while those in present tense are hypothetical innature, though based on mix designs that have already been made.

Example 1

[0108] A dual cure dental composition suitable as an endodontic sealingor filling material was prepared in two parts, with each part having thefollowing components in the stated amounts: Part 1 triethylene glycoldimethacrylate 16.8% benzoyl peroxide  0.2% diurethane dimethacrylate30.0% bis glycerol dimethacrylate phosphate  5.0% bismuth chloride oxide40.0% calcium lactate pentahydrate  6.0% silicon dioxide  2.0% TotalPart 1:  100%

[0109] Part 2 triethylene glycol dimethacrylate 16.8% p-tolyiminodiethanol  0.2% phenyl bis(2,4,6-trimethyl benzoyl)  0.5% phosphineoxide diurethane dimethacrylate 30.0% bis glycerol dimethacrylatephosphate  5.0% bismuth chloride oxide 40.0% calcium lactatepentahydrate  5.5% silicon dioxide  2.0% Total Part 2:  100%

[0110] The final composition was made by mixing equal amounts of Parts 1and 2. Once mixed, the mixed composition was able to cure in less than 2hours, thus preventing or inhibiting leaching of monomers and othermaterials from the root canal into the surrounding dental tissues. Themixed composition was also capable of accelerated curing as a result ofirradiating the composition with radiant energy, such as by means of adental curing lamp.

Example 2

[0111] An adhesive antimicrobial dental composition was formed havingthe following components and concentrations: Percent by Weight Componentof the Mixture calcium hydroxide 10.0% bis-glycerol methacrylatephosphate 5.0% urethane dimethacrylate 57.0% triethylene glycoldimethacrylate 6.0% titanium dioxide 1.0% calcium phosphate tribasic10.0% dimethyl amino ethyl methacrylate 0.5% camphorquinone 0.2% bariumsulfate 10.3%

Example 3

[0112] In this example, an adhesive antimicrobial dental composition isformed having the following composition: Percent by Weight Component ofthe Mixture bis 2-hydroxy ethyl methacrylate 10.0% barium hydroxide25.0% calcium phosphate tribasic 5.0% benzoin ethyl ether 0.4%N-methylethanol amine 0.5% glycerol dimethacrylate 59.1%

Example 4

[0113] In this example, an adhesive antimicrobial dental composition isformed having the following composition: Percent by Weight Component ofthe Mixture strontium oxide 30.0% camphorquinone 0.5% diethyl aminoethyl methacrylate 0.5% bis glyceryl methacrylate phosphate 69.0%

Example 5

[0114] In this example, an adhesive antimicrobial dental composition isformed having the following composition: Percent by Weight Component ofthe Mixture cetyl pyridinium chloride  4.0% strontium chloride 10.0%2-hydroxy-2-methyl-1-phenyl-1-propanone  0.5% diphenyl2,4,6-trimethylbenzoyl phosphine oxide  0.5% xanthomycin  1.0% phosphateester of 4-hydroxy butyl methacrylate 29.0% butane diol dimethacrylate55.0%

Example 6

[0115] In this example, an adhesive antimicrobial dental composition isformed having the following composition: Percent by Weight Component ofthe Mixture penicillin N 3.5% silicon dioxide fumed 16.0% bis-glycerylmethacrylate phosphate 3.0% benzophenone 1.0% tri hexyl amine 1.5%calcium phosphate tribasic 10.0% bis 2-hydroxy ethyl methacrylate 4.0%triethylene glycol dimethacrylate 61.0%

Example 7

[0116] In this example, an adhesive antimicrobial dental composition isformed having the following composition: Percent by Weight Component ofthe Mixture 4′-sulfamoylsulfanilanilide 1.0% 1,1′-hexamethylene bis(5(p-chlorophenyl) 1.0% biguanide) phosphate ester of 3-hydroxy propylmethacrylate 5.0% urethane dimethacrylate 92.0% benzoin ethyl ether 1.0%2-dimethylaminoethanol 1.0%

Example 8

[0117] In this example, an adhesive antimicrobial dental composition isformed having the following composition: Percent by Weight Component ofthe Mixture magnesium oxide 15.0% barium chloride 40.0%9,10-anthraquinone 0.9% triethylamine 0.3% bis glyceryl methacrylatephosphate 43.8%

[0118] The present invention may be embodied in other specific formswithout departing from its spirit or essential characteristics. Thedescribed embodiments are to be considered in all respects only asillustrative and not restrictive. The scope of the invention is,therefore, indicated by the appended claims rather than by the foregoingdescription. All changes which come within the meaning and range ofequivalency of the claims are to be embraced within their scope.

What is claimed is:
 1. A method for treating a tooth following anendodontic procedure comprising: providing a tooth that has been cleanedby en endodontic procedure and that includes an access hole drilled intoand extending through the crown of the tooth that provides access to atleast one root canal of the tooth; mixing together initially separateparts of a multipart endodontic composition to form a mixed compositionwhich is initially flowable and suitable for placement into a root canalduring a root canal procedure and which hardens over time, the mixedcomposition initially including: a polymerizable resin portion includingan adhesive resin that is at least one of an alkyl acrylate or alkylmethacrylate and capable of bonding to dental tissue found within a rootcanal; at least one chemical initiator which causes at least a portionof the polymerizable resin portion to polymerize over a period of time;and at least one polymerization photoinitiator which, upon irradiatingat least a portion of the mixed composition with radiant energy, causesaccelerated polymerization and hardening of at least a portion of thepolymerizable resin portion; introducing the mixed composition into theat least one root canal of the tooth; irradiating with radiant energy anexposed portion of the mixed composition in order to acceleratepolymerization and hardening of at least the exposed portion of themixed composition; and filling the access hole with a filling material.2. A method for treating a tooth as defined in claim 1, wherein theadhesive resin has an initial concentration in a range from about 0.01%to about 90% by weight of the mixed composition.
 3. A method fortreating a tooth defined in claim 1, wherein the adhesive resin has aninitial concentration in a range from about 0.5% to about 30% by weightof the mixed composition.
 4. A method for treating a tooth defined inclaim 1, wherein the adhesive resin has an initial concentration in arange from about 1% to about 10% by weight of the mixed composition. 5.A method for treating a tooth defined in claim 1, wherein thepolymerizable resin portion further includes at least one additionalpolymerizable resin comprising at least one of an alkyl acrylate, analkyl methacrylate, an alkyl hydroxy methacrylate, an alkyl aminomethacrylate, or bisphenol-A-diglycidyl dimethacrylate.
 6. A method fortreating a tooth as defined in claim 5, wherein the at least oneadditional polymerizable resin has an initial concentration of up toabout 95% by weight of the mixed composition.
 7. A method for treating atooth as defined in claim 5, wherein the at least one additionalpolymerizable resin has an initial concentration in a range from about5% to about 80% by weight of the mixed composition.
 8. A method fortreating a tooth as defined in claim 5, wherein the at least oneadditional polymerizable resin has an initial concentration in a rangefrom about 10% to about 70% by weight of the mixed composition.
 9. Amethod for treating a tooth as defined in claim 1, wherein the at leastone chemical initiator includes a plurality of initially separate andunmixed components, each component being contained in a different one ofthe initially separate parts of the multipart endodontic composition.10. A method for treating a tooth as defined in claim 9, wherein the atleast one chemical initiator includes a peroxide-based componentcontained in one of the initially separate parts and an amino componentcontained in a different one of the initially separate parts.
 11. Amethod for treating a tooth as defined in claim 10, wherein theperoxide-based component includes at least one of benzoyl peroxide,2-butanone peroxide, lauroyl peroxide, or tert-butyl peroxide.
 12. Amethod for treating a tooth as defined in claim 10, wherein the aminocomponent includes at least one of dimethylamino ethyl methacrylate,triethyl amine, 2-dimethylamino ethanol, diethylamino ethylmethacrylate, trihexyl amine, N,N-dimethyl-p-toluidine,N-methylethanolamine, or 2,2′(p-tolyimino) diethanol.
 13. A method fortreating a tooth as defined in claim 1, wherein the at least onepolymerization photoinitiator includes at least one of camphor quinone,benzoin methyl ether, 2-hydroxy-2-methyl-1-phenyl-1-propanone, diphenyl2,4,6-trimethylbenzoyl phosphine oxide, benzoin ethyl ether,benzophenone, or 9,10-anthraquinone.
 14. A method for treating a toothas defined in claim 1, the multipart endodontic composition furtherincluding a radiopaque filler contained in at least one of the initiallyseparate parts that is at least one of a bismuth salt, silver, a silversalt, a barium salt, a strontium salt, a tungsten-containing compound,or titanium dioxide.
 15. A method for treating a tooth as defined inclaim 1, the multipart endodontic composition further including at leastone of silica or calcium phosphate tribasic contained in at least one ofthe initially separate parts.
 16. A method for treating a tooth asdefined in claim 1, the multipart endodontic composition furtherincluding at least one antimicrobial agent contained in at least one ofthe initially separate parts.
 17. A method for treating a tooth asdefined in claim 1, wherein the multipart composition includes twoinitially separate and unmixed parts.
 18. A method for treating a toothas defined in claim 1, wherein the filling material chemically bonds tothe exposed portion of the mixed composition.
 19. A method for treatinga tooth as defined in claim 1, wherein the mixed composition isintroduced into the root canal by means of a cannula sized to fit withinthe root canal and in fluid communication with a high pressure hydraulicsystem.
 20. A method for treating a tooth as defined in claim 1, furtherincluding the step of applying additional pressure to the mixedcomposition after introducing it into the root canal but prior to theirradiating step.
 21. A method for treating a tooth as defined in claim20, wherein the step of applying additional pressure is carried out bymeans of inserting an elastomeric plug into a said access hole andapplying force to said plug in order to exert pressure onto the mixedcomposition, said elastomeric plug being sized so as to form asubstantially fluid-tight seal between said plug and dental tissuesurrounding said access hole.
 22. A method for treating a tooth asdefined in claim 21, wherein said elastomeric plug comprises guttapercha.
 23. A method for treating a tooth as defined in claim 1, whereinthe chemical initiator is included in an amount so that thepolymerizable resin portion within the mixed composition cures in a timeperiod of about 20 minutes to about 2 hours as a result of chemicalcuring.
 24. A method for treating a tooth as defined in claim 1, whereinthe polymerization photoinitiator is included in an amount so that thepolymerizable resin portion within the mixed composition cures in a timeperiod of about 10 seconds to about 1 minute when the mixed compositionis irradiated with radiant energy.
 25. A method for treating a tooth asdefined in claim 1, wherein irradiating the exposed portion of the mixedcomposition causes accelerated polymerization and hardening of at leasta portion of the mixed composition in the root canal.
 26. A method fortreating a tooth as defined in claim 1, wherein the exposed portion ofthe mixed composition is disposed within the access hole.
 27. A methodfor treating a tooth as defined in claim 26, wherein irradiating theexposed portion of the mixed composition causes acceleratedpolymerization and hardening of at least a portion of the mixedcomposition in the root canal.
 28. A method for treating a toothcomprising: preparing an access hole within a tooth so as to expose atleast one root canal of the tooth; performing an endodontic procedure soas to clean the root canal; mixing together initially separate parts ofa multipart endodontic composition to form a mixed composition which isinitially flowable and suitable for placement into a root canal andwhich hardens over time, the mixed composition initially including: apolymerizable resin portion including an adhesive resin that is at leastone of an alkyl acrylate or alkyl methacrylate that promotes bonding todental tissue found within a root canal; at least one chemical initiatorwhich causes at least a portion of the polymerizable resin portion topolymerize over a period of time; and at least one polymerizationphotoinitiator which, upon irradiating at least a portion of the mixedcomposition with radiant energy, causes accelerated polymerization andhardening of at least a portion of the polymerizable resin portion;introducing the mixed composition into the at least one root canal ofthe tooth; irradiating with radiant energy an exposed portion of themixed composition in order to polymerize and harden at least the exposedportion of the mixed composition; and introducing a filling materialinto the access hole.
 29. A method for treating a tooth as defined inclaim 28, wherein irradiating the exposed portion of the mixedcomposition causes accelerated polymerization and hardening of at leasta portion of the mixed composition in the root canal.
 30. A method fortreating a tooth as defined in claim 28, wherein the exposed portion ofthe mixed composition is disposed within the access hole.
 31. A methodfor treating a tooth as defined in claim 30, wherein irradiating theexposed portion of the mixed composition causes acceleratedpolymerization and hardening of at least a portion of the mixedcomposition in the root canal.
 32. A method for sealing a root canal ofa tooth following an endodontic procedure comprising: providing a tooththat includes at least one exposed root canal that has been cleaned byan endodontic procedure; mixing together initially separate parts of amultipart endodontic composition to form a mixed composition which isinitially flowable and suitable for placement into a root canal andwhich hardens over time, the mixed composition initially including: apolymerizable resin portion including an adhesive resin that is at leastone of an alkyl acrylate or alkyl methacrylate and that promotes bondingto dental tissue found within a root canal; at least one chemicalinitiator which causes at least a portion of the polymerizable resinportion to polymerize over a period of time; and at least onepolymerization photoinitiator which, upon irradiating at least a portionof the mixed composition with radiant energy, causes acceleratedpolymerization and hardening of at least a portion of the polymerizableresin portion; introducing the mixed composition into the at least oneroot canal of the tooth; and irradiating with radiant energy an exposedportion of the mixed composition in order to accelerate polymerizationand hardening of at least the exposed portion of the mixed composition.33. A method for treating a tooth as defined in claim 32, whereinirradiating the exposed portion of the mixed composition causesaccelerated polymerization and hardening of at least a portion of themixed composition in the root canal.
 34. A method for sealing a rootcanal as defined in claim 32, further comprising providing an accesshole through the crown of the tooth to provide access to the root canal.35. A method for treating a tooth as defined in claim 34, wherein theexposed portion of the mixed composition is disposed within the accesshole.
 36. A method for treating a tooth as defined in claim 35, whereinirradiating the exposed portion of the mixed composition causesaccelerated polymerization and hardening of at least a portion of themixed composition in the root canal.
 37. A method for sealing a rootcanal as defined in claim 34, further comprising introducing a fillingmaterial into the access hole and causing or allowing the fillingmaterial to harden.
 38. A method for sealing a root canal as defined inclaim 37, wherein the filling material chemically bonds to theendodontic composition.
 39. A method for sealing a root canal as definedin claim 32, wherein the at least one chemical initiator includes aplurality of initially separate and unmixed components, each componentbeing contained in a different one of the initially separate parts ofthe multipart endodontic composition.
 40. A method for sealing a rootcanal as defined in claim 39, wherein the at least one chemicalinitiator includes a peroxide-based component contained in one of theinitially separate parts and an amino component contained in a differentone of the initially separate parts.
 41. A method for sealing a rootcanal as defined in claim 40, wherein the peroxide-based componentincludes at least one of benzoyl peroxide, 2-butanone peroxide, lauroylperoxide, or tert-butyl peroxide.
 42. A method for sealing a root canalas defined in claim 40, wherein the amino component includes at leastone of dimethylamino ethyl methacrylate, triethyl amine, 2-dimethylaminoethanol, diethylamino ethyl methacrylate, trihexyl amine,N,N-dimethyl-p-toluidine, N-methylethanolamine, or 2,2′(p-tolyimino)diethanol.
 43. A method for sealing a root canal as defined in claim 32,wherein the at least one polymerization photoinitiator includes at leastone of camphor quinone, benzoin methyl ether,2-hydroxy-2-methyl-1-phenyl-1-propanone, diphenyl2,4,6-trimethyl-benzoyl phosphine oxide, benzoin ethyl ether,benzophenone, or 9,10-anthraquinone.
 44. A method for sealing a rootcanal as defined in claim 32, the multipart endodontic compositionfurther including a radiopaque filler contained in at least one of theinitially separate parts that is at least one of a bismuth salt, silver,a silver salt, a barium salt, a strontium salt, a tungsten-containingcompound, or titanium dioxide.
 45. A method for sealing a root canal asdefined in claim 32, the multipart endodontic composition furtherincluding at least one of silica or calcium phosphate tribasic containedin at least one of the initially separate parts.
 46. A method forsealing a root canal as defined in claim 32, the multipart endodonticcomposition further including at least one antimicrobial agent containedin at least one of the initially separate parts.
 47. A method forsealing a root canal as defined in claim 32, wherein the mixedcomposition is introduced into the root canal by means of a cannulasized to fit within the root canal and in fluid communication with ahigh pressure hydraulic system.
 48. A method for treating a toothfollowing an endodontic procedure comprising: providing a tooth thatincludes an access hole drilled into and extending through the crown ofthe tooth, said access hole providing access to at least one root canalof the tooth that has been cleaned by an endodontic procedure; mixingtogether initially separate parts of a multipart endodontic compositionto form a mixed composition which is initially flowable and suitable forplacement into a root canal during a root canal procedure and whichhardens over time, the mixed composition initially including: apolymerizable resin portion including an adhesive resin that is at leastone of an alkyl acrylate or alkyl methacrylate and capable of bonding todental tissue found within a root canal, the adhesive resin comprisingat least one of glycidyl dimethacrylate, 2-hydroxy ethyl methacrylate,3-hydroxy propyl methacrylate; 4-hydroxy butyl methacrylate, ortriethylene glycol dimethacrylate; and at least one chemical initiatorwhich causes at least a portion of the polymerizable resin portion topolymerize over a period of time; introducing the mixed composition intothe at least one root canal of the tooth; allowing the mixed compositionto at least partially polymerize and form a hardened endodonticcomposition; and filling the access hole with a filling material.
 49. Amethod for treating a tooth as defined in claim 48, the mixedcomposition initially further including a diluent monomer.
 50. A methodfor treating a tooth as defined in claim 48, the filling materialcomprising a composite resin that forms a chemical bond with theendodontic composition.
 51. A method for treating a tooth as defined inclaim 48, the endodontic composition completely hardening after fillingthe access hole with the filling material.